the difference between cranking and running is the bleed down speed ( dynamic cam timing ) the faster the motor turns the less chance of the air backing up the intake tract due to the piston rinsing on the intake cycle . the faster the motor turns hemholz effects will start to take over and can "ram " air down the intake tract thru the ...
To find total overlap, check valve timing at 0.1mm valve lift as a checking height, if the valve motion is symmetrical at that lift, our example spec card cam which has a intake duration of 270 degrees and an exhaust duration of 256 degrees at 0.1mm will have valve timing events of IVO 24 BTDC / IVC 66 ABDC - EVO58 BBDC / EVC 18 ATDC giving an ...